JP5377292B2 - Eye accommodation measuring device - Google Patents

Description

  The present invention relates to an eye accommodation measuring apparatus.

  Conventionally, it has a far target that is a distant fixation target and a near target that is a near fixation target, and moves the near target from the focus position of the near target toward the eye. The near point, which is the position where the outline of the near target starts to blur when it is moved, and the far point where the outline of the far target starts to blur when moving the far target away from the focus position of the far target There is known an eye accommodation power measuring device that measures the eye accommodation power expressed by the difference in eye refraction at each point, near point and far point (Yoshihisa Oguchi, 3 others, “Ophthalmology Handbook”) 4th edition (pages 65-66), June 1, 2005, see the Medical School, Inc.).

  In this eye accommodation power measurement device, a far point is measured using a distance target, a near point is measured using a near distance target, and a difference between both positions is calculated to obtain the eye accommodation power. .

  However, in the conventional eye accommodation measuring device, it is necessary to replace the visual target and the additional lens for optometry in order to measure the near point and the far point, so it takes time to find the eye accommodation force, There was a problem that it was difficult to use.

  The present invention has been made in view of such circumstances, and an object of the present invention is to make it easier to measure the eye's accommodation power without the need to replace the visual target.

In order to solve the above problems, the present invention provides display means for displaying images for focusing on the far point side and near point side, and an optical system for observing the image displayed on the display means, Driving means for moving the optical system along the optical axis in accordance with an instruction from the outside; and when the optical system is moved to the far point side by the driving means, the image from the focus position on the far point side of the image The eye adjustment is calculated based on the position at which the image starts to blur and the position at which the image starts to blur from the focus position on the near point side of the image when the optical system is moved to the near point side by the driving unit. Control means, and the control means is configured such that the moving speed of the optical system from the focus position on the far point side of the image to the position at which the image starts to blur is the focus speed on the far point side from the initial position. The optical system up to the position The drive means is controlled to be slower than the moving speed to the far point side, and the moving speed to the near point side of the optical system from the focus position on the near point side of the image to the position where the image starts to blur is initial. The drive unit is controlled to be slower than the moving speed of the optical system from the position to the near point side focus position toward the near point side .

  Preferably, in the present invention, an instruction from the outside is performed by a push button provided on a housing that accommodates the display unit, the optical system, the driving unit, and the control unit. The drive means is controlled so that the optical system moves along the optical axis only while the push button is pressed.

  Preferably, in the present invention, each position of the position where the image starts to blur from the far-point side focus position and the position where the image starts to blur from the near-point side focus position are specified as The control means is instructed by a push button.

  Preferably, according to the present invention, the focus position on the far point side is instructed to the control means by the push button, and the control means is far from the focus position on the far point side of the optical system after this instruction. The drive means is controlled to slow down the moving speed to the point side, and the focus position on the near point side is instructed to the control means by the push button, and the control means, after this instruction, the control means of the optical system The drive means is controlled so as to slow down the moving speed from the near point side focus position to the near point side.

  According to the present invention, it is possible to make it easier to measure the eye's accommodation power without the need to replace the visual target and the additional lens for optometry.

FIG. 1 is a plan view of an eye accommodation measuring apparatus according to an embodiment of the present invention. FIG. 2 is a conceptual diagram illustrating a configuration of an eye accommodation force measuring apparatus. FIG. 3 is a block diagram for explaining a method of using the eye accommodation force measuring apparatus. FIG. 4 is a diagram showing an adjustment power age curve.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of an eye accommodation power measuring apparatus according to an embodiment of the present invention.

  A power button 11 (POWER), a focus button 12 (FOCUS), a start button 13 (START), and a mode button 14 (MODE) are provided on the upper surface of the housing 10 of the eye accommodation measuring apparatus.

  The power button 11 is a button for turning on / off the power of the eye accommodation measuring apparatus. When the power is turned on, images for focusing are displayed on LCDs (Liquid Crystal Displays) 40L and 40R (see FIG. 2) as display means.

  The focus button 12 is a button for moving the shift lenses 20L and 20R (see FIG. 2) along the optical axes L1 and L2 of the shift lenses 20L and 20R. The focus button 12 includes a push button 12a used when moving the shift lenses 20L and 20R in a direction away from the eyes and a push button 12b used when moving the shift lenses 20L and 20R in a direction approaching the eyes. . Focusing or the like can be performed by pressing the push buttons 12a and 12b.

  The start button 13 is a button for instructing the CPU 51 (see FIG. 4) to calculate the adjustment force.

  The mode button 14 is a button for selecting an image or the like displayed on the LCDs 40L and 40R (see FIG. 2). The mode button 14 has triangular selection keys 14a, 14b, 14c, 14d and a circular enter key 14e (ENTER). For example, when the enter key 14e is pressed after pressing the selection key 14b, the adjustment force measurement mode with one eye is selected, and when the enter key 14e is pressed after pressing the selection key 14d, the adjustment force measurement mode with both eyes is selected. When the enter key 14e is pressed after the selection key 14a is pressed, the measurement is performed only once. When the enter key 14e is pressed after the selection key 14c is pressed, the measurement is performed a plurality of times. If only the enter key 14e is continuously pressed for a predetermined time or longer, the images on the LCDs 40L and 40R are switched. When the enter key 14e is released, the image at that time is selected.

FIG. 2 is a conceptual diagram showing a configuration of an eye accommodation force measuring apparatus.
This eye accommodation power measuring apparatus includes left and right shift lenses 20L and 20R constituting an observation optical system, left and right dustproof glasses 30L and 30R, left and right LCDs 40L and 40R constituting display means, and control as control means. Circuit 50. The shift lenses 20L and 20R, the dustproof glasses 30L and 30R, the LCDs 40L and 40R, and the control circuit 50 are accommodated in the housing 10.

  The left LCD 40L and the left dustproof glass 30L are located on the optical axis L1 of the left shift lens 20L. The right LCD 40R and the right dustproof glass 30R are located on the optical axis L2 of the right shift lens 20R. The optical axis L1 and the optical axis L2 are parallel. The user looks into the images displayed on the LCDs 40L and 40R from the dust-proof glasses 30L and 30R through the shift lenses 20L and 20R. The LCDs 40L and 40R display images for focusing and measurement results. When the power is off, the shift lenses 20L and 20R are located at the initializing position IP that is the initial position.

  The left shift lens 20L is accommodated in the left fixed portion 21L. The right shift lens 20R is accommodated in the right fixing portion 21R. The left fixed portion 21L and the right fixed portion 21R are fixed to the fixed portion 21.

  Between the left and right shift lenses 20L and 20R of the fixed portion 21, bearings 27L and 27R are provided. A guide bar 25L is attached to the bearing 27L, and a guide bar 25R is attached to the bearing 27R so as to be movable relative to the bearings 27L and 27R, respectively. The guide bars 25L and 25R extend in the directions of the optical axes L1 and L2 of the shift lenses 20L and 20R, respectively. The guide bars 25L and 25R are fixed to the housing 10 by fixing means (not shown). With this configuration, the fixed portion 21 is supported by the guide bars 25L and 25R so as to be movable in the optical axis L1 and L2 directions via the bearings 27L and 27R. Therefore, when the fixed portion 21 moves in the direction of the optical axes L1 and L2, the shift lenses 20L and 20R also move in the direction of the optical axes L1 and L2 together with the fixed portion 21.

  The fixed portion 21 is an intermediate portion between the left and right shift lenses 20L and 20R, and extends in parallel with the optical axis L1 and L2 directions and is connected to a ball screw 22 connected to a stepping motor 23. The fixed portion 21 and the ball screw 22 are relatively movable in the directions of the optical axes L1 and L2. The fixing unit 21, the guide bars 25L and 25R, and the stepping motor 23 constitute driving means. When the stepping motor 23 is rotated, the fixed portion 21 moves in the direction of the optical axes L1 and L2 in conjunction with the rotation of the ball screw 22 connected to the stepping motor 23. The ball screw 22 has a fixed amount of movement in the direction of the optical axes L1 and L2 of the fixed portion 21 per one rotation (360 °). Therefore, by moving the stepping motor 23 forward / reversely, the initial position IP is the center, and the distance from the near point direction, which is the direction approaching the eye indicated by the solid line arrow in FIG. The shift lenses 20L and 20R can be moved in the direction of the far point, that is, the direction of the optical axes L1 and L2.

  Since the stepping motor 23 has a predetermined rotation angle per drive pulse, the amount of movement of the fixed portion 21 relative to the ball screw 22 can be detected by counting the number of drive pulses of the stepping motor 23. . Therefore, the position of the shift lens 20L, 20R in the optical axis direction with the initialization position IP of the shift lens 20L, 20R as the origin, for example, the focal point of the focusing image displayed on the LCD 40L, 40R on the far point side or near point side. The far point side or near point side focus position, which is the matching position, can be detected with high accuracy.

  The control circuit 50 moves the shift lens 20L, 20R from the focus position on the far point side of the focusing image displayed on the LCDs 40L, 40R, that is, the position where the image starts to blur, that is, the far point and the LCDs 40L, 40R. Based on the position at which the shift lenses 20L and 20R move from the focus position on the near point side of the displayed image for focusing and the image starts to blur, that is, the near point, the eye accommodation power is calculated. The control circuit 50 controls the moving direction, moving amount, moving speed, and the like of the shift lenses 20L and 20R. For example, the control circuit 50 moves the shift lenses 20L and 20R only while the focus button 12 is pressed, and the moving speed of the shift lenses 20L and 20R from the focus position of the focusing image to the position where the image starts to blur. However, the stepping motor 23 is driven so as to be slower than the moving speed of the shift lenses 20L and 20R from the initialization position IP to the focus position. This is effective for more accurately recognizing the point where the user starts to blur the image.

  In particular, this apparatus does not move the target as in the conventional apparatus, but moves the shift lenses 20L and 20R to form the image for focusing displayed on the target, that is, the LCDs 40L and 40R. Changing position. In conventional devices, the amount of movement of the target and the amount of movement of the target image change linearly, so if the refractive power of the user's eye lens is changed linearly, the target image always appears on the retina. In this apparatus, the amount of movement of the shift lenses 20L and 20R and the amount of movement of the imaging position are not linear in this apparatus. Therefore, the refractive power of the eyeball lens must also be changed nonlinearly. Therefore, it is important to control the moving speed of the shift lens 20 at the beginning of blurring of the focusing image.

  FIG. 3 is a block diagram for explaining the method of use and configuration of the eye accommodation power measuring device, and FIG. 4 is a view showing the accommodation age curve. In FIG. 4, the vertical axis and the horizontal axis are the adjustment force (D) and the age, respectively.

  The control circuit 50 is provided with a CPU 51, and a ROM 52 and a RAM 53 are connected to the CPU 51 via a bus. The ROM 52 stores various control programs including an adjustment power age curve and measurement results shown in FIG. 4, that is, an eye adjustment power, an age obtained from the adjustment power age curve, and an adjustment power measurement program. 4 is the same as that described in the non-patent document (page 66, FIG. 2). The RAM 53 stores calculation data.

Next, a method for using the eye accommodation measuring apparatus will be described with reference to FIG.
First, the power button 11 is pressed. The power is turned on and images for focusing are displayed on the LCDs 40L and 40R. At this time, the image can be switched by pressing the enter key 14e for a predetermined time or longer. The push button 12a (see FIG. 1) is pressed while viewing the image according to the instructions displayed on the LCDs 40L and 40R, and the shift lenses 20L and 20R are moved from the initialization position IP to the far-point focus position.

  When the shift lenses 20L and 20R reach the far-point focus position, the finger is released from the push button 12a and the enter key 14e is pressed. Thereafter, the push button 12a is pressed again to slightly move the shift lenses 20L and 20R away from the eyes. When the shift lenses 20L and 20R reach the position where the image starts to blur (-position), the far point is determined by pressing the enter key 14e. This position is stored in the RAM 53 of the CPU 51 as far point data. As described above, the movement speed of the shift lenses 20L and 20R after the enter key 14e is pressed when the shift lenses 20L and 20R reach the far-point focus position is slower than before the enter key 14e is pressed. Is preferred.

Here, a more accurate and simple method for measuring eye accommodation is described.
In this measurement method, first, the mode button 14 is used to change the measurement mode to the second adjustment force measurement mode, and the shift lenses 20L and 20R are moved to the far point side and the near point side by the above-described operation and the operation described later, respectively. When the shift lenses 20L and 20R reach the far-point and near-point focus positions, the positions at which the image starts to blur are input while displaying the focus position detection marks at those positions. This is a method for measuring the accommodation power of the eye as soon as these series of inputs are completed. The details are as follows.

  First, the measurement mode is set to the second adjustment force measurement mode by the mode button 14. Then, an operation method for allowing the user to input the far-point and near-point focus positions is displayed on the screens of the LCDs 40L and 40R. When the user performs an operation to input the far-point focus position according to the display, the shift lenses 20L and 20R move from the initialization position IP to the far-point side. At this time, for example, a focus position detection mark (hereinafter referred to as a position detection mark) is displayed at the upper left corner of the screen of the LCD 40L, 40R, and while the shift lenses 20L, 20R move from the initialization position IP to the far-point focus position. The position detection mark blinks, and when the far-point focus position is reached, the position detection mark is switched from blinking display to lighting display. As a result, the user is notified that the shift lenses 20L and 20R have reached the far-point focus position, and the user presses the enter key 14e at the position where the image starts to blur from this position based on this lighting display. To do. The same operation is performed on the near point side. In this way, the focus position can be objectively recognized, and the position where the image starts to blur is confirmed and input from that position, so that the user's labor can be reduced and accurate measurement can be performed. it can. The above is a method for measuring the eye accommodation more accurately and easily.

  Next, an operation method after determining the far point will be described. After the far point is determined, the push button 12b (see FIG. 1) is pressed while viewing the image according to the instructions displayed on the LCDs 40L and 40R, and the shift lenses 20L and 20R are moved from the initialization position IP to the focus position on the near point side. Let

  When the shift lenses 20L and 20R reach the near-point focus position, the finger is released from the push button 12b and the enter key 14e is pressed. The push button 12b is pushed again, and the shift lenses 20L and 20R are slightly moved in the direction approaching the eyes. Also at this time, it is preferable that the moving speed of the shift lenses 20L and 20R after the enter key 14e is pressed is slower than that before the enter key 14e is pressed. When the shift lenses 20L and 20R reach the position where the image starts to blur (+ position), the enter key 14e is pressed to determine the near point. This position is stored as near-point data in the RAM 53 of the CPU 51.

  Thereafter, the start button 13 is pressed. Based on the data stored in the RAM 53, the CPU 51 calculates the difference between the far point and the near point, which are adjustment force measurement values.

  Further, the CPU 51 refers to the adjustment power age curve stored as a default value in the ROM 52, obtains the age, and displays it on the LCDs 40L and 40R together with the adjustment power.

  According to this embodiment, the adjustment force can be obtained by simply pressing the focus button 12 or the like in accordance with the instructions displayed on the LCDs 40L and 40R, and the near-point and far-point targets and optometry as in the conventional example. There is no need to replace the additional lens. Further, since the shift lenses 20L and 20R are moved only while the focus button 12 is pressed, it is easy to detect the focus position. Further, if the moving speed of the shift lenses 20L, 20R from the focus position to the position where the image starts to blur is slower than the moving speed of the shift lenses 20L, 20R from the initialization position IP to the focus position, the far position where the image starts to blur. It is easier to detect points and near points. Further, unlike the conventional example, two replaceable visual targets and additional lenses for optometry are not required, so that the size can be reduced. Further, since the shift lenses 20L and 20R and the LCDs 40L and 40R are accommodated in the housing 10, the images of the LCDs 40L and 40R are easy to see and the adjustment power is easily determined without being affected by disturbance light. In addition, since the stepping motor 23 is employed, the adjustment force can be measured with higher accuracy than the conventional example, and the age of the eye can be obtained with higher accuracy.

  In the above embodiment, the adjustment force measurement mode with both eyes is selected. However, the adjustment key measurement mode with one eye can be selected by pressing the selection key 14b to turn off one LCD (for example, LCD 40L).

  In the above embodiment, the mode for measuring the far point and the near point and obtaining the adjustment force only once is selected, but the mode for obtaining the adjustment force by measuring the far point and the near point a plurality of times by pressing the selection key 14c. Can also be selected. When this mode is selected, the maximum and minimum measured values of far and near points that have been performed multiple times are cut, the adjustment force is calculated using the remaining measured values, and the average value is adjusted. After calculating the average value of the remaining measurement values as the force, the adjustment force is calculated using this, and displayed as the adjustment force on the LCDs 40L and 40R.

  Furthermore, in the above embodiment, the shift lenses 20L and 20R are moved in the optical axis direction, but the LCDs 40L and 40R may be moved in the optical axis direction instead.

  In the above embodiment, the two LCDs 40L and 40R are provided, but only one LCD may be provided. In this case, a plurality of reflecting mirrors and shutters for guiding the image displayed on the LCD to the left and right shift lenses 20L and 20R are arranged on the optical path.

Claims (4)

Display means for displaying images for focusing on the far point side and the near point side;
An optical system for observing the image displayed on the display means;
Driving means for moving the optical system along the optical axis in accordance with an instruction from the outside;
The position at which the image starts to blur from the focus position on the far point side of the image when the optical system is moved to the far point side by the driving means, and the optical system is moved to the near point side by the driving means. Control means for calculating an eye accommodation power based on a position at which the image starts to blur from a focus position on the near point side of the image .
The control means is configured so that the moving speed of the optical system from the focus position on the far point side of the image to the position where the image starts to blur is from the initial position to the focus position on the far point side. The driving means is controlled so as to be slower than the moving speed to the far point side, and the moving speed to the near point side of the optical system from the focus position on the near point side of the image to the position where the image starts to blur is An apparatus for measuring eye accommodation power , wherein the driving means is controlled so as to be slower than a moving speed of the optical system from an initial position to a focus position on the near point side toward the near point side .   An instruction from the outside is given by a push button provided in a housing that accommodates the display means, the optical system, the drive means, and the control means, and the control means is only while the push button is being pushed. The eye accommodation force measuring apparatus according to claim 1, wherein the driving unit is controlled so that the optical system moves along the optical axis.   Identification of each position of the position where the image starts to blur from the far-point side focus position and the position where the image starts to blur from the near-point side focus position is instructed to the control means by the push button. The apparatus for measuring an accommodation force of an eye according to claim 2. The far-point focus position is instructed to the control means by the push button, and the control means slows the moving speed of the optical system from the far-point focus position to the far-point side after this instruction. The focus means on the near point side is instructed to the control means by the push button, and the control means, after this instruction, is closer to the near point side than the focus position on the near point side of the optical system. 3. The eye accommodation force measuring apparatus according to claim 2 , wherein the driving means is controlled to slow down the moving speed to the eye.

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